[LIVY-376][DOCS] Update README with new naming and links and move Doc…

…s into separate files

[LIVY-376](https://issues.cloudera.org/browse/LIVY-376)

 * The README has been updated to match our new Apache naming and links.
 * The API Documentation has been split into separate files
 * Examples have been moved to the website apache/incubator-livy-website#5

This PR will be followed up with a way to build out the Docs for the website

Author: Alex Bozarth <[email protected]>

Closes apache#21 from ajbozarth/readme.

NOTICE.txt

@@ -1,4 +1,4 @@
-Apache livy
+Apache Livy
 Copyright 2017 The Apache Software Foundation
 
 This product includes software developed at

README.md

@@ -0,0 +1,82 @@
+# Apache Livy
+
+[![Build Status](https://travis-ci.org/apache/incubator-livy.svg?branch=master)](https://travis-ci.org/apache/incubator-livy)
+
+Apache Livy is an open source REST interface for interacting with
+[Apache Spark](http://spark.apache.org) from anywhere. It supports executing snippets of code or
+programs in a Spark context that runs locally or in
+[Apache Hadoop YARN](http://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/YARN.html).
+
+* Interactive Scala, Python and R shells
+* Batch submissions in Scala, Java, Python
+* Multiple users can share the same server (impersonation support)
+* Can be used for submitting jobs from anywhere with REST
+* Does not require any code change to your programs
+
+[Pull requests](https://github.com/apache/incubator-livy/pulls) are welcomed! But before you begin,
+please check out the [Contributing](http://livy.incubator.apache.org/community#Contributing)
+section on the [Community](http://livy.incubator.apache.org/community) page of our website.
+
+## Online Documentation
+
+Guides and documentation on getting started using Livy, example code snippets, and Livy API
+documentation can be found at [livy.incubator.apache.org](http://livy.incubator.apache.org).
+
+## Before Building Livy
+
+To build Livy, you will need:
+
+Debian/Ubuntu:
+  * mvn (from ``maven`` package or maven3 tarball)
+  * openjdk-7-jdk (or Oracle Java7 jdk)
+  * Python 2.6+
+  * R 3.x
+
+Redhat/CentOS:
+  * mvn (from ``maven`` package or maven3 tarball)
+  * java-1.7.0-openjdk (or Oracle Java7 jdk)
+  * Python 2.6+
+  * R 3.x
+
+MacOS:
+  * Xcode command line tools
+  * Oracle's JDK 1.7+
+  * Maven (Homebrew)
+  * Python 2.6+
+  * R 3.x
+
+Required python packages for building Livy:
+  * cloudpickle
+  * requests
+  * requests-kerberos
+  * flake8
+  * flaky
+  * pytest
+
+
+To run Livy, you will also need a Spark installation. You can get Spark releases at
+https://spark.apache.org/downloads.html.
+
+Livy requires at least Spark 1.6 and supports both Scala 2.10 and 2.11 builds of Spark, Livy
+will automatically pick repl dependencies through detecting the Scala version of Spark.
+
+Livy also supports Spark 2.0+ for both interactive and batch submission, you could seamlessly
+switch to different versions of Spark through ``SPARK_HOME`` configuration, without needing to
+rebuild Livy.
+
+
+## Building Livy
+
+Livy is built using [Apache Maven](http://maven.apache.org). To check out and build Livy, run:
+
+```
+git clone https://github.com/apache/incubator-livy.git
+cd livy
+mvn package
+```
+
+By default Livy is built against Apache Spark 1.6.2, but the version of Spark used when running
+Livy does not need to match the version used to build Livy. Livy internally uses reflection to
+mitigate the gaps between different Spark versions, also Livy package itself does not
+contain a Spark distribution, so it will work with any supported version of Spark (Spark 1.6+)
+without needing to rebuild against specific version of Spark.